Article information
Year 2021 Volume 71 Issue 1 Page 53-63
Title:
Effects of Alveolar Bone Width and Density on the Rate of Orthodontic Tooth Movement
Keyword(s):
Bone density, Bone width, Cone-beam computed tomography, Orthodontic tooth movement
Abstract:
Accelerated orthodontic tooth movement (OTM) has been widely explored. However, the influence of individual characteristics of alveolar bone on the rate of OTM has not been fully investigated. Therefore, this study aimed to evaluate the influence of morphological features and the density of the alveolar process on the rate of OTM. The study included 24 participants (15 females, 9 males) with an average age of 20.9 years (SDĀ± 3.4 years). Maxillary canines were retracted for three months using a standardized OTM protocol with segmental archwires and superelastic NiTi closed coil springs (50 gm) to provide light continuous force. No functional or localized occlusal interferences affected tooth movement. Pre- and post-canine retraction records were obtained with an intraoral dental scanner from which 3D dental models were created and superimposed to evaluate the amount and rate of OTM. Pre-treatment cone-beam computed tomography images of patients were used to measure alveolar bone width and density on the distal aspect of each canine. The correlation between the rate of OTM and the measured variables was investigated. The results show the mean rate OTM was 0.91 mm/month (range 0.80 - 1.03 mm/month). The rate of OTM was weakly positively correlated with the alveolar bone width to root ratio (r = 0.334, P < 0.05) and negatively correlated with cortical bone density (r = -0.297, P < 0.05). A wide range of OTM variation (range 0.04 - 0.86 mm/month) within the same individual, between right and left sides was observed in 75 % of cases indicating an asymmetric OTM pattern. The rate of OTM is influenced by alveolar bone width to root ratio and bone density which vary within the same individual. Teeth with higher bone width to root ratio and lower density tend to move faster than those with a lower ratio and higher density.